DIFFERENT OF WATER RESIDENCE TIME ON BIOFILTRATION IN RELATION TO IMPROVE WATER QUALITY AND FISH PRODUCTION ON AN INTENSIVE NILE TILAPIA (Oreochromis niloticus) CULTURE

Anang Hari Kristanto*, Imam Taufik, and Eri Setiadi
 Institute for Freshwater Aquaculture Research and Development
 ananghari25@gmail.com

Water pollution on the water body is the main problem in developing counties, including Indonesia. Municipal waste has containing high biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), total ammonia (TAN), and nitrite concentrations that inhibit fish growth, survival and low in fish production. The filters which can be passed through by the suitable water residence time should be constructed in order to reduce the pollutants.

The objectives were to increase the efficiency of biofiltration in reducing BOD, COD, TSS, TDS, ammonia, and nitrite concentrations, and to utilize the filtered water for growing fish.

The treatments of this experiment were as followed: A) 2 hours, B) 4 hours C) 6 hours of water residence time; D) control (without biofiltration). Each treatment consisted of three replicated. The fish with size of 2-3 cm in total length were introduced into the concrete tank with water volume of 9 m3 and the fish density of 150 ind./m3.

The water residence time showed significantly affect in reducing the pollutants such as BOD, COD, TSS, TAN, and nitrite among the treatment which 4 hours of water residence time was better in reducing BOD, COD, TSS, TAN, and nitrite than  the others (Table 1). The survival, growth, and biomass of fish at 4 hours water residence time was the highest (P<0.05) compared to the others (Table 2). This indicated that the biofiltration was effectively in relation to improve water quality and fish productivity.